Purpose To determine whether there were gender differences in full professorship after accounting for factors known to influence academic advancement. Materials and Methods Institutional review board approval was obtained for this HIPAA-compliant study, with waiver of informed consent. In this cross-sectional study, the authors used a comprehensive 2014 physician database (5089 academic radiologists, inclusive of all U.S. academic radiologists in 2014; 11.3% of all U.S. radiologists) containing information on physician age, years since residency, National Institutes of Health funding, scientific publications (first or last author and total), clinical trial investigation, and clinical volume measured according to 2013 Medicare reimbursement. Primary outcome of gender differences in full professorship was estimated by using a multilevel logistic regression model adjusting for these factors. Results Among 5089 academic radiologists, 3638 (71.5%) were men. The average age for male and female radiologists was 52 and 49 years, respectively. Overall, 239 women (16.5%) and 948 (26.1%) men were full professors (P < .001). Women had fewer total and first or last author publications than men (total, 12.2 vs 17.6; first or last, 6.8 vs 10.7; P < .001 for both comparisons). Women were less likely than men to have National Institutes of Health funding (2.0% vs 3.6%; P = .004) and generated less annual Medicare revenue ($63 346 vs $75 854; P = .001). After multivariate adjustment, rates of full professorship among female and male radiologists were not significantly different (absolute adjusted difference for female vs male radiologists, -1.5%; 95% confidence interval: -3.8%, 0.9%). Conclusion Among radiologists with U.S. medical school faculty appointments in 2014, men and women were similarly likely to be full professor after several factors known to influence promotion were taken into account. However, unadjusted differences in promotion and research productivity were present, which suggests that female radiologists may lack equal research opportunities. RSNA, 2016.